Most of us are curious about what may lie ahead – but would you really want to know if you had a high chance of inheriting an incurable disease?
This is closer to becoming a reality for more people, with Health Secretary Matt Hancock recently announcing the NHS may sell patients their genetic data to find out what their future health may hold.
But some families are already facing this difficult dilemma. Families such as Carli Pirie’s, from Biggleswade, Bedfordshire, which includes her brother and sister and her two cousins – Jack Bradshaw, 29, and his brother Tom, 32, from Stevenage, Hertfordshire.
That’s because their family carries a rare faulty gene linked to early onset Alzheimer’s. Their mothers, Tracey and Nicole, and their maternal grandmother, Ann, all developed the condition, and the cousins have a 50 per cent chance of being affected, too.
The vast majority of Alzheimer’s cases – 99 per cent – are not thought to be caused by a single gene. While there are around 20 genes associated with a higher risk of Alzheimer’s, these are believed to have only a small effect on whether people develop it.
But in early onset Alzheimer’s, three faulty genes have been identified; if you inherit one of them, you will develop the disease.
Carli’s mum, aunt and grandmother all have one of them, called amyloid precursor protein (APP); the others are presenilin 1 and 2.
These genes are involved in the production of a protein called amyloid. If one of these genes is faulty, there can be an abnormal build-up of the protein in the brain that causes clumps or plaques, a characteristic feature of Alzheimer’s.
These ‘big lumps of sticky protein gunge up the brain and make it difficult for brain cells to communicate with each other, and eventually they kill the brain cells’, explains Dr David Reynolds, chief scientific officer at the charity Alzheimer’s Research UK.
For Carli, 31, her siblings and her cousins, witnessing their mothers’ rapid descent into dementia within just a few years has been distressing enough – both now live in care homes and barely recognise their families. But they also live with the knowledge that they have a 50 per cent chance of developing the same disease.
‘We could all find out tomorrow if we have the faulty gene or not – but so far none of us has chosen to do so,’ says Carli, a construction project coordinator who lives with partner Alex, 35, who runs an engineering company, and her daughter Olivia, ten.
‘It’s not an easy decision to make, as we have all witnessed what our grandmother and my mum and her sister have all gone through, but there’s no cure or effective treatment yet.’
Carli’s grandmother Ann developed Alzheimer’s aged just 48 in 1987 and died at 65, having not recognised her loved ones for many years.
However, at the time she was diagnosed the family were unaware the disease was hereditary – the APP gene was not discovered until 1991.
‘Everyone gets more forgetful as they get older, but when Mum began …read more
Source:: Daily times